I don't care too much for the Terrainlinx roof system. Sure, it works, but there's a fundamental design decision that limits how the pieces can be interchanged. The trusses that support the roof pieces have some of the roof texture on them. That means, they can only be used with that particular roof type. I would love it if my Thoumonts and Friar sets could swap roof pieces whenever I wanted, but doing so requires tons more trusses to be custom built. Poo.
Here are some shots of a quick idea I'd like to push on: